CN110776497A - A preparation method for constructing two-dimensional organic layers based on cation-π interaction - Google Patents

Abstract

The invention relates to a preparation method for constructing a two-dimensional organic layer based on cation-π interaction, and three required building monomers are obtained by means of organic synthesis: 1,1', 1"-((2,4,6 -Trioxo-1,3,5-triazine-1,3,5-triyl)tris(ethane-2,1-diyl))tris(1-(2-(1H-indole-1) -yl)ethyl)-1H-imidazole-3-onium)hexafluorophosphate, potassium [1,1'-biphenyl]-4,4'-disulfonate and [1,1'-biphenyl]- Sodium 4,4'-disulfonate. These three monomers all include different cationic units and different π units, which compete for self-classification and recognition in solution, so that 1,1', 1"-( (2,4,6-trioxo-1,3,5-triazine-1,3,5-triyl)tris(ethane-2,1-diyl))tris(1-(2-( 1H-indol-1-yl)ethyl)-1H-imidazole-3-onium) hexafluorophosphate and potassium [1,1'-biphenyl]-4,4'-disulfonate (or [1, 1'-biphenyl]-4,4'-sodium disulfonate) effectively carries out molecular self-assembly, and by volatilizing the solvent, the supramolecular two-dimensional material 1 (or the supramolecular two-dimensional material 2) with high strength and good stability is obtained. ).

Description

A preparation method for constructing two-dimensional organic layers based on cation-π interaction

technical field

The invention belongs to the field of supramolecular materials, and relates to a preparation method for constructing a two-dimensional organic layer based on cation-π interaction.

Background technique

Two-dimensional materials based on cation-π self-assembly are a new type of supramolecular two-dimensional materials, which have high stability and modifiability, and can maintain well in various solvents, temperatures and complex mixed systems. stability. It has great application prospects in catalysis, conductive materials, flexible electronic materials, self-healing materials, etc. In addition, the synthesis of the corresponding monomers is simple and efficient, and can be prepared on a gram scale, so this method has a good reference value in the preparation of novel two-dimensional supramolecular materials.

Literature 1 "Guanjun Chang, Li Yang, Junxiao Yang, Mark P. Stoykovich, Xu Deng, Jiaxi Cui, and Dapeng Wang. High-Performance pH-Switchable Supramolecular Thermosets via Cation–πInteractions. Adv. Mater. 2018, 30, 17042, 34 ” discloses a preparation method of a recyclable cation-π cross-linked thermosetting resin, which obtains the cross-linked structure of high-performance polymer through cation-π interaction, which satisfies people’s demand for high thermal stability and high strength of high-performance polymer. This physical cross-linking method can be released under external "stimulation" conditions, so as to realize the recovery and recycling of polymers. The structures constructed in this study are still random three-dimensional polymers, and the direction of the cation-π interaction is not well regulated, making it used to construct two-dimensional materials.

Document 2 "Kang-Da Zhang, Jia Tian, David Hanifi, Yuebiao Zhang, Andrew Chi-Hau Sue, Tian-You Zhou, Lei Zhang, Xin Zhao, Yi Liu, and Zhan-Ting Li. Toward aSingle-Layer Two-Dimensional Honeycomb Supramolecular Organic Framework in Water.J.Am.Chem.Soc.2013,135,17913-17918" discloses a two-dimensional supramolecular organic framework constructed by host-guest interaction in an aqueous solution. This novel supramolecular two-dimensional The material construction method is simple, but the strength and stability of two-dimensional materials are not enough, and it is difficult to get out of solution and be applied in solid form.

Document 3 "Bo Song, Zhiqiang Wang, Senlin Chen, Xi Zhang, et al. The Introduction of π-π Stacking Moieties for Fabricating Stable Micellar Structure: Formation and Dynamics of Disklike Micelles. Angew. Chem. 2005, 117, 4809-4813" discloses a It is an efficient method for the preparation of supramolecular two-dimensional materials, but because it is constructed by amphiphilic molecules, it has high requirements on the type of solvent, and the selectivity of the solvent is relatively poor.

SUMMARY OF THE INVENTION

technical problem to be solved

In order to avoid the deficiencies of the prior art, the present invention proposes a preparation method for constructing a two-dimensional organic layer based on cation-π interaction, which overcomes the problems of poor stability of current two-dimensional supramolecular materials and poor regulation of cation-π interaction. question.

Technical solutions

A preparation method for constructing a two-dimensional organic layer based on cation-π interaction is characterized in that the steps are as follows:

Step 1: Dissolve 1,3,5-tris(2-hydroxyethyl)triazine-2,4,6-trione and triphenylphosphine with a molar ratio of 1:3.6 in anhydrous acetonitrile, ice bath Cool for 5 to 10 minutes; add 3.6 equivalents of carbon tetrabromide under constant stirring, return to room temperature while stirring, and react for 10 to 12 hours; remove the solvent under reduced pressure, dissolve the concentrated solution in an appropriate amount of dichloromethane, and then use The saturated aqueous sodium chloride solution was washed 1-2 times, the organic phases were combined, dried with anhydrous sodium sulfate, and the solvent was removed under reduced pressure to obtain a crude product;

The obtained crude product was separated by a gel chromatography column with n-hexane as the eluent to obtain 1,3,5-tris(2-bromoethyl)-1,3,5-triazacyclohexane as a white crystalline solid -2,4,6-triketone;

Step 2: Mix indole, 2-bromoethanol, tetrabutylammonium iodide and potassium hydroxide successively in a molar ratio of 1:2:0.1:3, add N,N-dimethylformamide as a solvent to obtain a solution; The solution was deoxygenated by Schlenk technology, heated to 80-90° C. and stirred for 20-24 hours under the protection of nitrogen atmosphere; after the reaction was completed, the reaction mixture was cooled to room temperature, the solvent was removed under reduced pressure, and the residue was used Separation by gel chromatography, the eluent is petroleum ether:ethyl acetate=3:1, to obtain 2-(1H-indol-1-yl)ethan-1-ol as a light yellow liquid;

Step 3: Mix 2-(1H-indol-1-yl)ethan-1-ol and triphenylphosphine in step 2 in a molar ratio of 1:1.2, add 100 ml of acetonitrile, and cool in an ice bath for 5-10 minutes; Add 1.2 equivalents of carbon tetrabromide, stir and slowly return to room temperature, and react for 5 to 6 hours; remove the solvent under reduced pressure, dissolve the concentrated solution in 100 ml of dichloromethane, and then wash twice with saturated aqueous sodium chloride solution, The organic phases were combined, dried over anhydrous sodium sulfate, and the solvent was removed under reduced pressure to obtain a crude product; the obtained crude product was separated by a gel chromatography column, and the eluent was n-hexane to obtain a yellow oily liquid 2-(1H-indole -1-yl) ethyl-1-bromo;

Step 4: Disperse sodium hydride in anhydrous 1,4-dioxane solution in a Schlenk flask, then add imidazole to the stirred mixed solution under nitrogen protection; then heat the mixture to 70-85°C Stir the reaction for 1.0 to 1.5 hours; then add the 2-(1H-indol-1-yl) ethyl-1-bromine obtained in step 3 into the reaction solution dropwise, after the system is stable, heat up to 100 to 105 ° C and reflux for 10 ~12 hours; after the reaction was completed, the reaction solution was cooled to room temperature, the solvent was removed under reduced pressure, and redissolved in 100 ml of dichloromethane, then washed twice with water, the organic phases were combined, dried over anhydrous sodium sulfate, and removed under reduced pressure solvent to obtain a crude product; the obtained crude product was separated by a gel chromatography column, and the eluent was ethyl acetate to obtain a red oily liquid 1-(2-(1H-imidazol-1-yl)ethyl)-1H- indole;

Step 5: Combine 1,3,5-tris(2-bromoethyl)-1,3,5-triazacyclohexane-2,4,6-trione obtained in step 1 with 1 obtained in step 4 -(2-(1H-imidazol-1-yl)ethyl)-1H-indole was mixed in a molar ratio of 1:4.5, 1,4-dioxane was added as a solvent, and heated to 100～105℃ Stir and reflux for 20 to 24 hours; after the reaction is completed, cool to room temperature, remove the solvent under reduced pressure, add tetrahydrofuran to precipitate a large amount of solid, filter, wash the filter cake with tetrahydrofuran 3 to 4 times, and dry to obtain a brownish yellow solid 1,1',1 "-((2,4,6-trioxo-1,3,5-triazine-1,3,5-triyl)tris(ethane-2,1-diyl))tris(1-( 2-(1H-Indol-1-yl)ethyl)-1H-imidazol-3-onium)bromide salt;

Step 6: The 1,1',1"-((2,4,6-trioxo-1,3,5-triazine-1,3,5-triyl)tris(ethane) obtained in step 5 -2,1-Diyl)) tris(1-(2-(1H-indol-1-yl)ethyl)-1H-imidazol-3-onium) bromide salt was dissolved in 50-70 mL methanol; under stirring Then, add saturated ammonium hexafluorophosphate methanol solution dropwise until the precipitation no longer separates out, continue stirring for 30-40 minutes; filter, wash the filter cake with methanol and water for 3-4 times each, and dry to obtain a yellow solid 1,1', 1"-((2,4,6-Trioxo-1,3,5-triazine-1,3,5-triyl)tris(ethane-2,1-diyl))tris(1- (2-(1H-Indol-1-yl)ethyl)-1H-imidazol-3-onium)hexafluorophosphate;

Step 7: Dissolve [1,1'-biphenyl]-4,4'-disulfonic acid and potassium hydroxide in deionized water in a molar ratio of 1:2, and stir the reaction solution at room temperature for 15-30 minutes , and then freeze-dried in vacuo to obtain white potassium [1,1'-biphenyl]-4,4'-disulfonate;

Step 8: The 1,1',1"-((2,4,6-trioxo-1,3,5-triazine-1,3,5- Triyl)tris(ethane-2,1-diyl))tris(1-(2-(1H-indol-1-yl)ethyl)-1H-imidazol-3-onium)hexafluorophosphate with The potassium [1,1'-biphenyl]-4,4'-disulfonate obtained in step 7 was dissolved in the dimethyl sulfoxide solution, and the complete dissolution was promoted by ultrasonic for 3 minutes; the pressure was reduced to -0.09～-0.1MPa , the solvent is completely removed at 90-95°C; after completion, the obtained solid is cooled to room temperature, which is a two-dimensional organic layer constructed based on cation-π interaction.

Replacing steps 7 and 8 with the following steps 7a and 8a, another two-dimensional organic layer based on cation-π interaction is obtained:

Step 7a: Dissolve [1,1'-biphenyl]-4,4'-disulfonic acid and sodium hydroxide in deionized water in a molar ratio of 1:2, stir at room temperature for 15-30 minutes, and then vacuum Freeze drying to obtain white sodium [1,1'-biphenyl]-4,4'-disulfonate;

Step 8a: 1,1',1"-((2,4,6-trioxo-1,3,5-triazine-1,3,5-(2,4,6-trioxo-1,3,5-triazine-1,3,5- Triyl)tris(ethane-2,1-diyl))tris(1-(2-(1H-indol-1-yl)ethyl)-1H-imidazol-3-onium)hexafluorophosphate with The sodium [1,1'-biphenyl]-4,4'-disulfonate obtained in step 7a is dissolved in the dimethyl sulfoxide solution, and ultrasonicated for 2-3 minutes to promote its complete dissolution; the pressure is reduced to -0.09～- The solvent was completely removed at 0.1 MPa at 90-95 °C; after completion, the obtained solid was cooled to room temperature, which is another two-dimensional organic layer constructed based on cation-π interaction.

The Schlenk technique is: after adding reactants and solvents into a dry Schlenk tube, first freezing with liquid nitrogen, under a nitrogen atmosphere, evacuating, then introducing nitrogen, and then freezing with liquid nitrogen again, thus repeating freezing-thawing- Freeze operation multiple times.

The anhydrous acetonitrile is the solvent after drying of 5A molecular sieve.

The 1,4-dioxane solvent is the solvent after drying of 5A molecular sieve.

All solution heatings were carried out under constant temperature oil bath conditions.

The ice-bath cooling of the solution was carried out under the condition of ice-water mixture at 0°C.

beneficial effect

A preparation method for constructing a two-dimensional organic layer based on cation-π interaction proposed in the present invention obtains two new supramolecular two-dimensional materials by means of the bottom-up self-assembly of supramolecules. First, three desired building blocks were obtained through a series of organic synthesis methods: 1,1',1"-((2,4,6-trioxo-1,3,5-triazine-1, 3,5-Triyl)tris(ethane-2,1-diyl))tris(1-(2-(1H-indol-1-yl)ethyl)-1H-imidazol-3-onium)hexa Fluorophosphate, potassium [1,1'-biphenyl]-4,4'-disulfonate and sodium [1,1'-biphenyl]-4,4'-disulfonate. All three monomers are Including different cationic moieties and different π moieties, in the solution through the competition for self-classification recognition, so that 1,1',1"-((2,4,6-trioxo-1,3,5 -Triazine-1,3,5-triyl)tris(ethane-2,1-diyl))tris(1-(2-(1H-indol-1-yl)ethyl)-1H-imidazole -3-Onium) hexafluorophosphate and potassium [1,1'-biphenyl]-4,4'-disulfonate (or sodium [1,1'-biphenyl]-4,4'-disulfonate ) effectively carry out molecular self-assembly, and by volatilizing the solvent, the supramolecular two-dimensional material 1 (or the supramolecular two-dimensional material 2) with high strength and good stability is obtained. This new type of two-dimensional material has great application prospects in catalysis, conductive materials, flexible electronic materials, self-healing materials, etc.

Description of drawings

Fig. 1 is (2,4,6-trioxo-1,3,5-triazine-1,3,5-triyl) tri(ethane-2,1-diyl) prepared by the method of the present invention Schematic diagram of the molecular structure of tris(1-(2-(1H-indol-1-yl)ethyl)-1H-imidazol-3-onium)hexafluorophosphate.

Figure 2 is a schematic diagram of the molecular structure of potassium [1,1'-biphenyl]-4,4'-disulfonate.

Figure 3 is a schematic diagram of the molecular structure of sodium [1,1'-biphenyl]-4,4'-disulfonate.

4 is a transmission electron microscope image of the two-dimensional supramolecular organic layer prepared in Example 1 of the method of the present invention.

Detailed ways

The present invention will now be further described in conjunction with the embodiments and accompanying drawings:

Example 1:

Step 1. Dissolve 1,3,5-tris(2-hydroxyethyl)triazine-2,4,6-trione (1.0 g, 3.82 mmol) and triphenylphosphine (3.6 g, 13.72 mmol) in anhydrous acetonitrile (100 mL), and cooled in an ice bath for 10 minutes. Carbon tetrabromide (4.56 g, 13.72 mmol) was added slowly with constant stirring. The mixture was stirred and slowly returned to room temperature for 12 hours. The solvent was removed under reduced pressure, the concentrated solution was dissolved in an appropriate amount of dichloromethane, and then washed twice with saturated aqueous sodium chloride solution and aqueous solution, respectively, the organic phases were combined, dried over anhydrous sodium sulfate, and the solvent was removed under reduced pressure to obtain a crude product. The obtained crude product was separated by a gel chromatography column with n-hexane as the eluent to obtain 1,3,5-tris(2-bromoethyl)-1,3,5-triazacyclohexane as a white crystalline solid -2,4,6-trione (90% yield).

Step 2. Indole (1.0g, 8.53mmol), 2-bromoethanol (2.13g, 17.1mmol), tetrabutylammonium iodide (0.31g, 0.85mmol) and potassium hydroxide were successively added to the single-necked round bottom flask (1.4 g, 25.6 mmol), 100 ml of N,N-dimethylformamide was added as a solvent. The above solution was deoxygenated by the Schlenk technique, after which the solution was heated to 80°C under nitrogen atmosphere and the reaction was stirred for 24 hours. After the reaction was completed, the reaction mixture was cooled to room temperature, the solvent was removed under reduced pressure, the residue was separated by a gel chromatography column, and the eluent was petroleum ether:ethyl acetate=3:1 to obtain a pale yellow liquid 2-( 1H-Indol-1-yl)ethan-1-ol (70% yield).

Step 3. Add 2-(1H-indol-1-yl)ethan-1-ol (2.0g, 12.4mmol) and triphenylphosphine (3.9g, 14.9mmol) to a single-necked round-bottomed flask in turn, add 50ml Acetonitrile, cooled in an ice bath for 10 minutes. Carbon tetrabromide (4.9 g, 14.9 mmol) was added slowly with constant stirring. The mixture was stirred and slowly returned to room temperature for 6 hours. The solvent was removed under reduced pressure, the concentrated solution was dissolved in an appropriate amount of dichloromethane, and then washed twice with saturated aqueous sodium chloride solution and aqueous solution, respectively, the organic phases were combined, dried over anhydrous sodium sulfate, and the solvent was removed under reduced pressure to obtain a crude product. The obtained crude product was separated by a gel chromatography column with n-hexane as the eluent to obtain 2-(1H-indol-1-yl)ethane-1-bromide (yield 84%) as a yellow oily liquid.

Step 4. Disperse sodium hydride (64%) (0.27 g, 6.7 mmol) in 20 ml of anhydrous 1,4-dioxane solution in a Schlenk flask. Then imidazole (0.46 g, 6.7 mmol) was slowly added to the stirred mixed solution under nitrogen protection. The mixture was then heated to 70°C and the reaction was stirred for 1.5 hours. Then 2-(1H-indol-1-yl)ethane-1-bromide (1.0 g, 4.5 mmol) obtained in step 3 was slowly added dropwise to the reaction solution, and after the system was stable, the temperature was raised to 105° C. and refluxed for 12 hours. . After the reaction was completed, the reaction solution was cooled to room temperature, the solvent was removed under reduced pressure, and redissolved in an appropriate amount of dichloromethane, then washed twice with water, the organic phases were combined, dried over anhydrous sodium sulfate, and the solvent was removed under reduced pressure to obtain a crude product. The obtained crude product was separated by a gel chromatography column, and the eluent was ethyl acetate to obtain a red oily liquid 1-(2-(1H-imidazol-1-yl)ethyl)-1H-indole (yield 85 %).

Step 5. Combine 1,3,5-tris(2-bromoethyl)-1,3,5-triazacyclohexane-2,4,6-trione (0.2g, 0.45mmol) and 1- (2-(1H-imidazol-1-yl)ethyl)-1H-indole (0.64g, 2.69mmol) was added to a single-necked flask, 25ml of 1,4-dioxane was added as a solvent, and heated to 105°C Stir and reflux for 24 hours. After the reaction was completed, it was cooled to room temperature, the solvent was removed under reduced pressure, a large amount of solid was precipitated after adding tetrahydrofuran, filtered, and the filter cake was washed three times with tetrahydrofuran, and dried to obtain a brown solid 1,1',1"-((2,4,6 -Trioxo-1,3,5-triazine-1,3,5-triyl)tris(ethane-2,1-diyl))tris(1-(2-(1H-indole-1) -yl)ethyl)-1H-imidazol-3- onium)bromide salt (78% yield).

Step 6. Convert 1,1',1"-((2,4,6-trioxo-1,3,5-triazine-1,3,5-triyl)tri(ethane-2,1 -diyl)) tris(1-(2-(1H-indol-1-yl)ethyl)-1H-imidazole-3- onium) bromide salt was dissolved in an appropriate amount of methanol. Under constant stirring, slowly dropwise Saturated methanol solution of ammonium hexafluorophosphate until the precipitation no longer precipitated, and continued stirring for 30 minutes. Filtration, the filter cake was washed three times with methanol and water, and dried to obtain a yellow solid 1,1',1"-((2,4 ,6-Trioxo-1,3,5-triazine-1,3,5-triyl)tris(ethane-2,1-diyl))tris(1-(2-(1H-indole) -1-yl)ethyl)-1H-imidazol-3- onium)hexafluorophosphate (90% yield).

Step 7. [1,1'-biphenyl]-4,4'-disulfonic acid (100 mg, 0.318 mmol) and potassium hydroxide (35.7 mg, 0.636 mmol) were dissolved in 10 ml of deionized water. The reaction solution was stirred at room temperature for 30 minutes, and then freeze-dried in vacuo to obtain white potassium [1,1'-biphenyl]-4,4'-disulfonate (99% yield).

Step 8. Convert 1,1',1"-((2,4,6-trioxo-1,3,5-triazine-1,3,5-triyl)tri(ethane-2,1 -diyl))tris(1-(2-(1H-indol-1-yl)ethyl)-1H-imidazol-3- onium)hexafluorophosphate (89.5 mg, 0.070 mmol) and [1,1 '-biphenyl]-4,4'-potassium disulfonate (8.9 mg, 0.023 mmol) was dissolved in 3.0 ml of dimethyl sulfoxide solution, and ultrasonicated for 3 minutes to promote its complete dissolution. Reduce the pressure to -0.1 MPa, 90 The solvent was slowly and completely removed at °C. After completion, the obtained solid was cooled to room temperature, which was a two-dimensional organic layer constructed based on cation-π interaction.

Example 2:

Replace steps 7 and 8 with steps 7a and 8a:

Step 7a. [1,1'-biphenyl]-4,4'-disulfonic acid (100 mg, 0.318 mmol) and sodium hydroxide (25.4 mg, 0.636 mmol) were dissolved in 10 ml of deionized water. The reaction solution was stirred at room temperature for 30 minutes, and then freeze-dried in vacuo to obtain white sodium [1,1'-biphenyl]-4,4'-disulfonate (99% yield).

Step 8a, convert 1,1',1"-((2,4,6-trioxo-1,3,5-triazine-1,3,5-triyl)tri(ethane-2,1 -diyl))tris(1-(2-(1H-indol-1-yl)ethyl)-1H-imidazol-3- onium)hexafluorophosphate (89.5 mg, 0.070 mmol) and [1,1 '-biphenyl]-4,4'-sodium disulfonate (8.23mg, 0.023mmol) was dissolved in 3.0ml of dimethyl sulfoxide solution, and ultrasonicated for 3 minutes to promote its complete dissolution. Reduce the pressure to -0.1MPa, 90 The solvent was slowly and completely removed at ° C. After completion, the obtained solid 3 was cooled to room temperature, which was another two-dimensional organic layer constructed based on cation-π interaction.

Example 3:

Step 1. Dissolve 1,3,5-tris(2-hydroxyethyl)triazine-2,4,6-trione (2.0 g, 7.64 mmol) and triphenylphosphine (7.2 g, 27.48 mmol) in anhydrous acetonitrile (200 mL), and cooled in an ice bath for 10 minutes. Carbon tetrabromide (9.12 g, 27.44 mmol) was added slowly with constant stirring. The mixture was stirred and slowly returned to room temperature for 12 hours. The solvent was removed under reduced pressure, the concentrated solution was dissolved in an appropriate amount of dichloromethane, and then washed twice with saturated aqueous sodium chloride solution and aqueous solution, respectively, the organic phases were combined, dried over anhydrous sodium sulfate, and the solvent was removed under reduced pressure to obtain a crude product. The obtained crude product was separated by a gel chromatography column with n-hexane as the eluent to obtain 1,3,5-tris(2-bromoethyl)-1,3,5-triazacyclohexane as a white crystalline solid -2,4,6-trione (90% yield).

Step 2. Indole (2.0g, 16.06mmol), 2-bromoethanol (4.26g, 34.2mmol), tetrabutylammonium iodide (0.62g, 1.70mmol) and potassium hydroxide were successively added to the single-necked round-bottomed flask (2.8 g, 51.2 mmol), 200 ml of N,N-dimethylformamide was added as a solvent. The above solution was deoxygenated by the Schlenk technique, after which the solution was heated to 80°C under nitrogen atmosphere and the reaction was stirred for 24 hours. After the reaction was completed, the reaction mixture was cooled to room temperature, the solvent was removed under reduced pressure, the residue was separated by a gel chromatography column, and the eluent was petroleum ether:ethyl acetate=3:1 to obtain a pale yellow liquid 2-( 1H-Indol-1-yl)ethan-1-ol (70% yield).

Step 3. Add 2-(1H-indol-1-yl)ethan-1-ol (4.0g, 24.8mmol) and triphenylphosphine (7.8g, 29.8mmol) to a single-necked round-bottomed flask in turn, add 100ml Acetonitrile, cooled in an ice bath for 10 minutes. Carbon tetrabromide (9.8 g, 29.8 mmol) was added slowly with constant stirring. The mixture was stirred and slowly returned to room temperature for 6 hours. The solvent was removed under reduced pressure, the concentrated solution was dissolved in an appropriate amount of dichloromethane, and then washed twice with saturated aqueous sodium chloride solution and aqueous solution, respectively, the organic phases were combined, dried over anhydrous sodium sulfate, and the solvent was removed under reduced pressure to obtain a crude product. The obtained crude product was separated by a gel chromatography column with n-hexane as the eluent to obtain 2-(1H-indol-1-yl)ethane-1-bromide (yield 84%) as a yellow oily liquid.

Step 4. Disperse sodium hydride (64%) (0.54 g, 13.4 mmol) in 40 ml of anhydrous 1,4-dioxane solution in a Schlenk flask. Then imidazole (0.92 g, 13.4 mmol) was slowly added to the stirred mixed solution under nitrogen protection. The mixture was then heated to 70°C and the reaction was stirred for 1.5 hours. Then 2-(1H-indol-1-yl)ethane-1-bromide (2.0 g, 9.0 mmol) obtained in step 3 was slowly added dropwise to the reaction solution, and after the system was stabilized, the temperature was raised to 105° C. and refluxed for 12 hours . After the reaction was completed, the reaction solution was cooled to room temperature, the solvent was removed under reduced pressure, and redissolved in an appropriate amount of dichloromethane, then washed twice with water, the organic phases were combined, dried over anhydrous sodium sulfate, and the solvent was removed under reduced pressure to obtain a crude product. The obtained crude product was separated by a gel chromatography column, and the eluent was ethyl acetate to obtain a red oily liquid 1-(2-(1H-imidazol-1-yl)ethyl)-1H-indole (yield 85 %).

Step 5. Combine 1,3,5-tris(2-bromoethyl)-1,3,5-triazacyclohexane-2,4,6-trione (0.4 g, 0.9 mmol) and 1- (2-(1H-imidazol-1-yl)ethyl)-1H-indole (1.28g, 5.38mmol) was added to a single-necked flask, 50ml of 1,4-dioxane was added as a solvent, and heated to 105°C Stir and reflux for 24 hours. After the reaction was completed, it was cooled to room temperature, the solvent was removed under reduced pressure, a large amount of solid was precipitated after adding tetrahydrofuran, filtered, and the filter cake was washed three times with tetrahydrofuran, and dried to obtain a brown solid 1,1',1"-((2,4,6 -Trioxo-1,3,5-triazine-1,3,5-triyl)tris(ethane-2,1-diyl))tris(1-(2-(1H-indole-1) -yl)ethyl)-1H-imidazol-3- onium)bromide salt (78% yield).

Step 6. Convert 1,1',1"-((2,4,6-trioxo-1,3,5-triazine-1,3,5-triyl)tri(ethane-2,1 -diyl)) tris(1-(2-(1H-indol-1-yl)ethyl)-1H-imidazole-3- onium) bromide salt was dissolved in an appropriate amount of methanol. Under constant stirring, slowly dropwise Saturated methanol solution of ammonium hexafluorophosphate until the precipitation no longer precipitated, and continued stirring for 30 minutes. Filtration, the filter cake was washed three times with methanol and water, and dried to obtain a yellow solid 1,1',1"-((2,4 ,6-Trioxo-1,3,5-triazine-1,3,5-triyl)tris(ethane-2,1-diyl))tris(1-(2-(1H-indole) -1-yl)ethyl)-1H-imidazol-3- onium)hexafluorophosphate (90% yield).

Step 7. [1,1'-biphenyl]-4,4'-disulfonic acid (200 mg, 0.636 mmol) and potassium hydroxide (71.4 mg, 1.272 mmol) were dissolved in 20 ml of deionized water. The reaction solution was stirred at room temperature for 30 minutes, and then freeze-dried in vacuo to obtain white potassium [1,1'-biphenyl]-4,4'-disulfonate (99% yield).

Step 8. Convert 1,1',1"-((2,4,6-trioxo-1,3,5-triazine-1,3,5-triyl)tri(ethane-2,1 -diyl))tris(1-(2-(1H-indol-1-yl)ethyl)-1H-imidazol-3- onium)hexafluorophosphate (179.0 mg, 0.140 mmol) and [1,1 '-biphenyl]-4,4'-potassium disulfonate (17.8 mg, 0.046 mmol) was dissolved in 6.0 ml of dimethyl sulfoxide solution, and ultrasonicated for 3 minutes to promote its complete dissolution. Reduce the pressure to -0.1 MPa, 90 The solvent was slowly and completely removed at °C. After completion, the obtained solid was cooled to room temperature, which was a two-dimensional organic layer constructed based on cation-π interaction.

Example 4:

Replace steps 7 and 8 with steps 7a and 8a:

Step 7a. [1,1'-biphenyl]-4,4'-disulfonic acid (200 mg, 0.636 mmol) and sodium hydroxide (50.8 mg, 1.272 mmol) were dissolved in 20 ml of deionized water. The reaction solution was stirred at room temperature for 30 minutes, and then freeze-dried in vacuo to obtain white sodium [1,1'-biphenyl]-4,4'-disulfonate (99% yield).

Step 8a, convert 1,1',1"-((2,4,6-trioxo-1,3,5-triazine-1,3,5-triyl)tri(ethane-2,1 -diyl))tris(1-(2-(1H-indol-1-yl)ethyl)-1H-imidazol-3- onium)hexafluorophosphate (179.0 mg, 0.140 mmol) and [1,1 '-Biphenyl]-4,4'-Sodium disulfonate (16.46mg, 0.046mmol) was dissolved in 6.0ml dimethyl sulfoxide solution, and ultrasonicated for 3 minutes to promote its complete dissolution. Reduce the pressure to -0.1MPa, 90 The solvent was slowly and completely removed at °C. After completion, the obtained solid was cooled to room temperature, which is another two-dimensional organic layer based on cation-π interaction.

Example 5:

Step 1. Dissolve 1,3,5-tris(2-hydroxyethyl)triazine-2,4,6-trione (3.0 g, 11.46 mmol) and triphenylphosphine (10.8 g, 41.16 mmol) in anhydrous acetonitrile (300 mL), and cooled in an ice bath for 10 minutes. Carbon tetrabromide (13.68 g, 41.16 mmol) was added slowly with constant stirring. The mixture was stirred and slowly returned to room temperature for 12 hours. The solvent was removed under reduced pressure, the concentrated solution was dissolved in an appropriate amount of dichloromethane, and then washed twice with saturated aqueous sodium chloride solution and aqueous solution, respectively, the organic phases were combined, dried over anhydrous sodium sulfate, and the solvent was removed under reduced pressure to obtain a crude product. The obtained crude product was separated by a gel chromatography column with n-hexane as the eluent to obtain 1,3,5-tris(2-bromoethyl)-1,3,5-triazacyclohexane as a white crystalline solid -2,4,6-trione (90% yield).

Step 2. Add indole (3.0g, 25.59mmol), 2-bromoethanol (6.39g, 51.3mmol), tetrabutylammonium iodide (0.93g, 2.55mmol) and potassium hydroxide successively to the single-necked round-bottomed flask (4.2 g, 76.8 mmol), 300 ml of N,N-dimethylformamide was added as a solvent. The above solution was deoxygenated by the Schlenk technique, after which the solution was heated to 80°C under nitrogen atmosphere and the reaction was stirred for 24 hours. After the reaction was completed, the reaction mixture was cooled to room temperature, the solvent was removed under reduced pressure, the residue was separated by a gel chromatography column, and the eluent was petroleum ether:ethyl acetate=3:1 to obtain a pale yellow liquid 2-( 1H-Indol-1-yl)ethan-1-ol (70% yield).

Step 3. Add 2-(1H-indol-1-yl)ethan-1-ol (6.0 g, 37.2 mmol) and triphenylphosphine (11.7 g, 44.7 mmol) to a single-necked round-bottomed flask, and add 150 ml Acetonitrile, cooled in an ice bath for 10 minutes. Carbon tetrabromide (14.7 g, 44.7 mmol) was added slowly with constant stirring. The mixture was stirred and slowly returned to room temperature for 6 hours. The solvent was removed under reduced pressure, the concentrated solution was dissolved in an appropriate amount of dichloromethane, and then washed twice with saturated aqueous sodium chloride solution and aqueous solution, respectively, the organic phases were combined, dried over anhydrous sodium sulfate, and the solvent was removed under reduced pressure to obtain a crude product. The obtained crude product was separated by a gel chromatography column with n-hexane as the eluent to obtain 2-(1H-indol-1-yl)ethane-1-bromide (yield 84%) as a yellow oily liquid.

Step 4. Disperse sodium hydride (64%) (0.81 g, 20.1 mmol) in 60 ml of anhydrous 1,4-dioxane solution in a Schlenk flask. Then imidazole (1.38 g, 20.1 mmol) was slowly added to the stirred mixed solution under nitrogen protection. The mixture was then heated to 70°C and the reaction was stirred for 1.5 hours. Then 2-(1H-indol-1-yl)ethane-1-bromide (3.0 g, 13.5 mmol) obtained in step 3 was slowly added dropwise to the reaction solution, and after the system was stabilized, the temperature was raised to 105° C. and refluxed for 12 hours. . After the reaction was completed, the reaction solution was cooled to room temperature, the solvent was removed under reduced pressure, and redissolved in an appropriate amount of dichloromethane, then washed twice with water, the organic phases were combined, dried over anhydrous sodium sulfate, and the solvent was removed under reduced pressure to obtain a crude product. The obtained crude product was separated by a gel chromatography column, and the eluent was ethyl acetate to obtain a red oily liquid 1-(2-(1H-imidazol-1-yl)ethyl)-1H-indole (yield 85 %).

Step 5. Combine 1,3,5-tris(2-bromoethyl)-1,3,5-triazacyclohexane-2,4,6-trione (0.6 g, 1.35 mmol) and 1- (2-(1H-imidazol-1-yl)ethyl)-1H-indole (1.92g, 8.07mmol) was added to a single-necked flask, 75ml of 1,4-dioxane was added as a solvent, and heated to 105°C Stir and reflux for 24 hours. After the reaction was completed, it was cooled to room temperature, the solvent was removed under reduced pressure, a large amount of solid was precipitated after adding tetrahydrofuran, filtered, and the filter cake was washed three times with tetrahydrofuran, and dried to obtain a brown solid 1,1',1"-((2,4,6 -Trioxo-1,3,5-triazine-1,3,5-triyl)tris(ethane-2,1-diyl))tris(1-(2-(1H-indole-1) -yl)ethyl)-1H-imidazol-3- onium)bromide salt (78% yield).

Step 6. Convert 1,1',1"-((2,4,6-trioxo-1,3,5-triazine-1,3,5-triyl)tri(ethane-2,1 -diyl)) tris(1-(2-(1H-indol-1-yl)ethyl)-1H-imidazole-3- onium) bromide salt was dissolved in an appropriate amount of methanol. Under constant stirring, slowly dropwise Saturated methanol solution of ammonium hexafluorophosphate until the precipitation no longer precipitated, and continued stirring for 30 minutes. Filtration, the filter cake was washed three times with methanol and water, and dried to obtain a yellow solid 1,1',1"-((2,4 ,6-Trioxo-1,3,5-triazine-1,3,5-triyl)tris(ethane-2,1-diyl))tris(1-(2-(1H-indole) -1-yl)ethyl)-1H-imidazol-3- onium)hexafluorophosphate (90% yield).

Step 7. [1,1'-biphenyl]-4,4'-disulfonic acid (300 mg, 0.954 mmol) and potassium hydroxide (107.1 mg, 1.908 mmol) were dissolved in 30 ml of deionized water. The reaction solution was stirred at room temperature for 30 minutes, and then freeze-dried in vacuo to obtain white potassium [1,1'-biphenyl]-4,4'-disulfonate (99% yield).

Step 8. Convert 1,1',1"-((2,4,6-trioxo-1,3,5-triazine-1,3,5-triyl)tri(ethane-2,1 -diyl))tris(1-(2-(1H-indol-1-yl)ethyl)-1H-imidazol-3- onium)hexafluorophosphate (268.5 mg, 0.210 mmol) and [1,1 '-biphenyl]-4,4'-potassium disulfonate (26.7 mg, 0.069 mmol) was dissolved in 9.0 ml of dimethyl sulfoxide solution, and ultrasonicated for 3 minutes to promote its complete dissolution. Reduce the pressure to -0.1 MPa, 90 The solvent was slowly and completely removed at °C. After completion, the obtained solid was cooled to room temperature, which was a two-dimensional organic layer constructed based on cation-π interaction.

Example 6:

Replace steps 7 and 8 with steps 7a and 8a:

Step 7a. [1,1'-biphenyl]-4,4'-disulfonic acid (300 mg, 0.954 mmol) and sodium hydroxide (71.2 mg, 1.908 mmol) were dissolved in 30 ml of deionized water. The reaction solution was stirred at room temperature for 30 minutes, and then freeze-dried in vacuo to obtain white sodium [1,1'-biphenyl]-4,4'-disulfonate (99% yield).

Step 8a, convert 1,1',1"-((2,4,6-trioxo-1,3,5-triazine-1,3,5-triyl)tri(ethane-2,1 -diyl))tris(1-(2-(1H-indol-1-yl)ethyl)-1H-imidazol-3- onium)hexafluorophosphate (268.5 mg, 0.210 mmol) and [1,1 '-Biphenyl]-4,4'-Sodium disulfonate (24.7mg, 0.069mmol) was dissolved in 9.0ml dimethyl sulfoxide solution, and ultrasonicated for 3 minutes to promote its complete dissolution. Reduce the pressure to -0.1MPa, 90 The solvent was slowly and completely removed at °C. After completion, the obtained solid was cooled to room temperature, which is another two-dimensional organic layer based on cation-π interaction.

Claims (7)

1. a preparation method based on cation-π interaction to build two-dimensional organic layer, is characterized in that step is as follows: Step 1: Dissolve 1,3,5-tris(2-hydroxyethyl)triazine-2,4,6-trione and triphenylphosphine with a molar ratio of 1:3.6 in anhydrous acetonitrile, ice bath Cool for 5 to 10 minutes; add 3.6 equivalents of carbon tetrabromide under constant stirring, return to room temperature while stirring, and react for 10 to 12 hours; remove the solvent under reduced pressure, dissolve the concentrated solution in an appropriate amount of dichloromethane, and then use The saturated aqueous sodium chloride solution was washed 1-2 times, the organic phases were combined, dried with anhydrous sodium sulfate, and the solvent was removed under reduced pressure to obtain a crude product; The obtained crude product was separated by a gel chromatography column with n-hexane as the eluent to obtain 1,3,5-tris(2-bromoethyl)-1,3,5-triazacyclohexane as a white crystalline solid -2,4,6-triketone; Step 2: Mix indole, 2-bromoethanol, tetrabutylammonium iodide and potassium hydroxide successively in a molar ratio of 1:2:0.1:3, add N,N-dimethylformamide as a solvent to obtain a solution; The solution was deoxygenated by Schlenk technology, heated to 80-90° C. and stirred for 20-24 hours under the protection of nitrogen atmosphere; after the reaction was completed, the reaction mixture was cooled to room temperature, the solvent was removed under reduced pressure, and the residue was used Separation by gel chromatography, the eluent is petroleum ether:ethyl acetate=3:1, to obtain 2-(1H-indol-1-yl)ethan-1-ol as a light yellow liquid; Step 3: Mix 2-(1H-indol-1-yl)ethan-1-ol and triphenylphosphine in step 2 in a molar ratio of 1:1.2, add 100 ml of acetonitrile, and cool in an ice bath for 5-10 minutes; Add 1.2 equivalents of carbon tetrabromide, stir and slowly return to room temperature, and react for 5 to 6 hours; remove the solvent under reduced pressure, dissolve the concentrated solution in 100 ml of dichloromethane, and then wash twice with saturated aqueous sodium chloride solution, The organic phases were combined, dried over anhydrous sodium sulfate, and the solvent was removed under reduced pressure to obtain a crude product; the obtained crude product was separated by a gel chromatography column, and the eluent was n-hexane to obtain a yellow oily liquid 2-(1H-indole -1-yl) ethyl-1-bromo; Step 4: Disperse sodium hydride in anhydrous 1,4-dioxane solution in a Schlenk flask, then add imidazole to the stirred mixed solution under nitrogen protection; then heat the mixture to 70-85°C Stir the reaction for 1.0 to 1.5 hours; then add the 2-(1H-indol-1-yl) ethyl-1-bromine obtained in step 3 into the reaction solution dropwise, after the system is stable, heat up to 100 to 105 ° C and reflux for 10 ~12 hours; after the reaction was completed, the reaction solution was cooled to room temperature, the solvent was removed under reduced pressure, and redissolved in 100 ml of dichloromethane, then washed twice with water, the organic phases were combined, dried over anhydrous sodium sulfate, and removed under reduced pressure solvent to obtain a crude product; the obtained crude product was separated by a gel chromatography column, and the eluent was ethyl acetate to obtain a red oily liquid 1-(2-(1H-imidazol-1-yl)ethyl)-1H- indole; Step 5: Combine 1,3,5-tris(2-bromoethyl)-1,3,5-triazacyclohexane-2,4,6-trione obtained in step 1 with 1 obtained in step 4 -(2-(1H-imidazol-1-yl)ethyl)-1H-indole was mixed in a molar ratio of 1:4.5, 1,4-dioxane was added as a solvent, and heated to 100～105℃ Stir and reflux for 20 to 24 hours; after the reaction is completed, cool to room temperature, remove the solvent under reduced pressure, add tetrahydrofuran to precipitate a large amount of solid, filter, wash the filter cake with tetrahydrofuran 3 to 4 times, and dry to obtain a brownish yellow solid 1,1',1 "-((2,4,6-trioxo-1,3,5-triazine-1,3,5-triyl)tris(ethane-2,1-diyl))tris(1-( 2-(1H-Indol-1-yl)ethyl)-1H-imidazol-3-onium)bromide salt; Step 6: The 1,1',1"-((2,4,6-trioxo-1,3,5-triazine-1,3,5-triyl)tris(ethane) obtained in step 5 -2,1-Diyl)) tris(1-(2-(1H-indol-1-yl)ethyl)-1H-imidazol-3-onium) bromide salt was dissolved in 50-70 mL methanol; under stirring Then, add saturated ammonium hexafluorophosphate methanol solution dropwise until the precipitation no longer separates out, continue stirring for 30-40 minutes; filter, wash the filter cake with methanol and water for 3-4 times each, and dry to obtain a yellow solid 1,1', 1"-((2,4,6-Trioxo-1,3,5-triazine-1,3,5-triyl)tris(ethane-2,1-diyl))tris(1- (2-(1H-Indol-1-yl)ethyl)-1H-imidazol-3-onium)hexafluorophosphate; Step 7: Dissolve [1,1'-biphenyl]-4,4'-disulfonic acid and potassium hydroxide in deionized water in a molar ratio of 1:2, and stir the reaction solution at room temperature for 15-30 minutes , and then freeze-dried in vacuo to obtain white potassium [1,1'-biphenyl]-4,4'-disulfonate; Step 8: The 1,1',1"-((2,4,6-trioxo-1,3,5-triazine-1,3,5- Triyl)tris(ethane-2,1-diyl))tris(1-(2-(1H-indol-1-yl)ethyl)-1H-imidazol-3-onium)hexafluorophosphate with The potassium [1,1'-biphenyl]-4,4'-disulfonate obtained in step 7 was dissolved in the dimethyl sulfoxide solution, and the complete dissolution was promoted by ultrasonic for 3 minutes; the pressure was reduced to -0.09～-0.1MPa , the solvent is completely removed at 90-95°C; after completion, the obtained solid is cooled to room temperature, which is a two-dimensional organic layer constructed based on cation-π interaction. 2. the preparation method of constructing two-dimensional organic layer based on cation-π interaction according to claim 1, is characterized in that: replace step 7 and step 8 with following step 7a and step 8a, obtain another kind based on cation-π Two-dimensional organic layer constructed by interaction: Step 7a: Dissolve [1,1'-biphenyl]-4,4'-disulfonic acid and sodium hydroxide in deionized water in a molar ratio of 1:2, stir at room temperature for 15-30 minutes, and then vacuum Freeze drying to obtain white sodium [1,1'-biphenyl]-4,4'-disulfonate; Step 8a: 1,1',1"-((2,4,6-trioxo-1,3,5-triazine-1,3,5-(2,4,6-trioxo-1,3,5-triazine-1,3,5- Triyl)tris(ethane-2,1-diyl))tris(1-(2-(1H-indol-1-yl)ethyl)-1H-imidazol-3-onium)hexafluorophosphate with The [1,1'-biphenyl]-4,4'-sodium disulfonate obtained in step 7a is dissolved in the dimethyl sulfoxide solution, and ultrasonicated for 2-3 minutes to promote its complete dissolution; the pressure is reduced to -0.09～- The solvent was completely removed at 0.1 MPa at 90-95 °C; after completion, the obtained solid was cooled to room temperature, which is another two-dimensional organic layer constructed based on cation-π interaction. 3. The preparation method for constructing a two-dimensional organic layer based on cation-π interaction according to claim 1 or 2, wherein the Schlenk technique is: after adding reactants and a solvent into a dry Schlenk tube, first use After freezing with liquid nitrogen, in a nitrogen atmosphere, vacuum is drawn, then nitrogen is introduced, and then frozen with liquid nitrogen again, so that the freezing-thawing-freezing operation is repeated many times. 4. The preparation method for constructing a two-dimensional organic layer based on cation-π interaction according to claim 1 or 2, wherein the anhydrous acetonitrile is a solvent after drying of 5A molecular sieve. 5 . The preparation method for constructing a two-dimensional organic layer based on cation-π interaction according to claim 1 or 2 , wherein the 1,4-dioxane solvent is a solvent after drying of 5A molecular sieve. 6 . 6 . The preparation method for constructing a two-dimensional organic layer based on cation-π interaction according to claim 1 or 2 , wherein all solutions are heated under constant temperature oil bath conditions. 7 . 7 . The preparation method for constructing a two-dimensional organic layer based on cation-π interaction according to claim 1 or 2 , wherein the solution is cooled in an ice bath at 0° C. of an ice-water mixture. 8 .

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